[lwip-users] Re: [lwip] Question and thoughts..

[David Ryan]

Jani Monoses wrote:

>  
>
>>Hi..
>>
>>I've recently downloaded lwip060rc1 and been working with that.  I 
>>finally got lwip so that I can *nearly* ping it from my pc, however 
>>ethereal is showing up that the ping response ICMP checksum is inccorect 
>>set as 0x335c ( should be 0x6e98 ).  Windows is throwing the response 
>>away as a bad packet.  I haven't started looking closely at the icmp or 
>>ip files yet..  but thought that this sort of error would not show up 
>>just in implementation?  Anyone have similar problem, or suggest how the 
>>environment might effect the outcome of the checksum?  The IP checksum 
>>is coming out correctly.
>>    
>>
>What platform do you run lwip on?
>  
>

Attempting :)  to run it on a playstation2 on the IOP(IO Processor) 
which is mips3000.  Playstation 2 has two processors..  one handling IO 
(which is actually the old playstation one chip) and the other (EE) 
handling the main programs.  I'm using a NetGear EA101 (Kawasaki 
chipset) over its USB connections.  This isn't related to playstaion2 
linux either.. this is direct access to the system.

On a different note.. is *anyone* using lwip in a multithreaded 
environment?  I'm currently looking closely at the mbox code used in the 
unix arch.. I've used it as the basis for the ps2.  One thing I noticed 
is that the mbox->mail semaphore gets posted when the first message is 
sent to the mbox.. but is never signalled when a message is removed. 
 I've added the following just after mbox->first++ in mbox_fetch.  This 
just resets the semaphore ready for next time when we've emptied the queue.

if ( mbox->first == mbox-> last )
   sys_sem_signal( mbox->mail );

I've still got a race condition which is causing the main thread to 
stall.  It could be in my implementation of sys_arch_sem_wait.  I'll 
keep searching.

David.

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